Tag Archives: QRP

A little off-line, off-grid camping

You might have noticed a lack of posts this weekend and that would be because I was completely off-grid and off-line, camping with two good friends in Pisgah National Forest.

It was brilliant, actually. I got to hang with friends I’ve known for over 30 years, test my new one person backpack tent (a.k.a. the “Bear Burrito”–the one on the right above), and of course I played a bit of radio.

Black bears are a fact of life here in the mountains of western North Carolina and we spotted three hanging out within 25 meters of our campsite.

By the way: the trick when camping with bears? Don’t put food in your tent, else that whole “bear burrito” thing becomes a reality.

I had a fabulous time putting my Elecraft KX1 “Ruby” on the air. I made perhaps 15 contacts in CW (Morse Code) with 3 watts of power.

One of the cool things about the KX1 is you can change the mode to SSB and actually tune through several shortwave broadcast bands (if you have the three or four band version of the KX1). Of course, I had to do a little SWLing.

As I mentioned in my previous post, I’m also a proper coffee snob and I firmly believe coffee tastes better when brewed outdoors. Yesterday morning, I brewed a pot of Rock Creek French Roast.

Off-grid, off-line camping recharges my internal batteries and it’s for this reason, I’ll be doing a lot more this year with my family.

It’s is also a brilliant way to experience an environment without any forms of radio interference (QRM or RFI). If you want to do some proper DXing, take your radio on some primitive camping experiences. It’ll remind you what life was like before switching power supplies ruled the world!

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My new-to-me TEN-TEC Argonaut V

While browsing the QTH.com classifieds last weekend, I found an ad for a Ten-Tec Argonaut V (Model 516).

The Argo V was a general coverage HF transceiver produced by TEN-TEC starting around 2003 or so. When it was introduced to market, I wanted one because I thought not only would it be a great QRP transceiver, but TEN-TEC rigs tended to have brilliant audio and were capable broadcast band receivers.

The seller described it as being in “pristine condition and operating to factory specs on all bands.”

The seller seemed to be a nice fellow and sent me a number of photos with his QSL card in the image and his email address matched what was on file with QRZ.com. The seller checked out on many levels confirming this wasn’t a scam (always assume a classifieds listing could be a scam!).

I purchased it last week and it was delivered today.

The first thing I did after connecting it to a power supply was tune to the 31 meter band, switch the mode to AM, and widen the variable filter to 6 kHz (the Argo’s max AM bandwidth).

So far, I’m impressed!

For a ham radio transceiver, I can tell that the Argo V is going to be a competent rig for casual shortwave radio listening.

I also tuned to the mediumwave band (not having even checked in advance its lower RX limit) and am happy to report that it covers the whole AM BC band as well.

If I’m being honest, though, the real reason I’ve always wanted an Argonaut V, specifically, is because I absolutely love the front panel design of this radio.

The large LED digit frequency display is fabulous and has–as my buddy Eric put it–a certain “Apollo era” aesthetic. The large frequency display was one of my favorite things about my beloved OMNI VI+ as well.

I’ll admit that I also love a good analog meter!

The Argonaut V also has a very simple, very Ten-Tec, front panel with good field ergonomics. In fact, the Argo V is a very simple radio: there are no modern features like message memory keying, built-in batteries, nor does it have an internal ATU.

Although spec-wise, I’ve much better receivers at SWLing Post HQ, I’m looking forward traveling the shortwaves with the Argo V!

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Guest Post: Dikeside Icom IC-705 RX action

Many thanks to SWLing Post contributor, 13dka, who shares the following guest post:


The IC-705 in action at the dike

by 13dka

When I got the IC-705 in late October 2020, I didn’t get that much chance to enjoy it at the dike: After a couple of initial tests and 2 nightly “FYBO” MW DX sessions in November, a way too long and wet winter struck the German North Sea coast, with nighttime temperatures recovering to 2-digit Celsius figures only in the past few weeks. I took the opportunity to do more experiments with loops, preamps and a phasing unit to improve the RFI-stricken reception at home, so I could at least listen to European hams on 80 and 40m raving about their new 705s and start to write my own musings about that lovely little radio, recently posted here.

SSB DX

June 1st, 202

Finally, acceptable temperatures at night! But they come with a downside: When I connected the vertical around 8:00pm (local time), it was still almost 2 hours before sunset and a lot of thunderstorms in Europe made even 14 MHz very noisy, my hopes for some nice catches were immediately taking a dive. A short scan of the bands brought up nothing special, the only notable thing being the CB and 10m bands being moderately open. I should’ve known better: As soon as the sun splashed into the ocean, grayline propagation worked its magic!

Grayline while receiving Japan, June 1st

As the image probably hints, a couple of Japanese “big guns” produced some nice, comfy signals on the monopole, in addition to the South American and Carribbean stations usually booming in here!

Video: A short collection of ham stations heard around midnight

After midnight I noticed a residue signal of WWV on 20 MHz and still a few EU beacons on 10m. Both incredibly weak with QSB making them disappear but that’s where the 705 really shines – it’s not only picking up these grassroots signals just fine, it shows me that they’re there, or that they were there – a waterfall display keeps on proving that a perceived lack of activity on a band is often pure bad luck – you can tune across an entire band without hearing anything because on each frequency with some activity there’s the other (inaudible to you) station speaking right now, QSB is dipping the signal just when you tune past it…

June 5/6, 2021

That evening the Japanese stations were missing on 20m, I thought I picked one up on 17m, and like so often, the one odd Australian station came in on 20m. After midnight I noticed the 10m beacons again, there were even a few more of them. This time I brought my Belka DSP to the dike so I could compare it with the IC-705, after all the Belka proved to be my most sensitive portable before! The devastating result is likely owed to the fact that the Belka is pretty picky about passive antennas not being matched very well to its input (which is much optimized for the whip) but it picked up diddly squat. If it isn’t a testimony for the sensitivity of the IC-705, it might be one for its aptitude to cope with all sorts of antennas.

Then I tuned into the 10m SSB range and I was veeeery surprised to hear VO1FOG from St. Johns, Canada! This is the first time I heard a transatlantic signal on 10m in a solar minimum ever, but it was with condx only elevated enough for some daytime DX within the EU…and literally in the middle of the night! The signal was very unstable though, he later switched to the 12m band which worked better. Back to what I said about the waterfall display above: Without it, I could’ve missed this station with a pretty high probability simply because I didn’t expect any activity up there, so I wouldn’t have tuned across that band for very long, and without seeing the signal while the VFO is already somewhere else…

I also heard another new country (Ecuador) in SSB, the usual collection of Carribbean islands and some participants of the “Museum Ships Weekend Event” including NI6IW, which is the vanity call of the history-charged USS Midway in San Diego. The “Japanese” station JW4GUA turned out to be on Svalbard island, with the main town Longyearbyen being the northernmost town in the world, only 650 miles from the north pole, and I don’t hear stations from there very often!

Video: June 5th

June 10/11

The past days saw the SFI passing 80 and 11/10m becoming quite busy. By the time I parked the car at the dike, SFI had dropped to 73. That evening the grayline confined itself to colorizing the horizon. 10m and 11m were still full of signals, I could still hear 2 British chaps chatting on 27 MHz at 3:00 in the morning, but nothing really “extraordinary” was coming in – the one odd VK, more Carribbean islands, one Argentinian but not much from other parts of South America, it never gets boring how this all defies predictability. But as always I heard most of the North American continent, not booming in much that night but I followed 2 POTA activations for a while, which are usually at most 100W stations working a lot of other “barefoot” stations and I heard almost all of them. In the morning grayline window for the west coast I finally got one solid signal from Oregon. All my radio life, the US west coast has been a tough target for some reason.

The signal had that typical “over the pole” sound, a relatively quick phasing imprinted into the signal by the charged particles converging over the pole, causing northern lights in the region and that exiting feeling when observing really big, planetary scale physics in realtime, over here at my listening post. The magic of shortwave. 🙂

Broadcast bands

After the post touting the IC-705 as a SWL/BCL receiver, demonstrating it on the broadcast bands seems mandatory to me. However, capturing cool BC DX is a very different business than waiting on the ham bands for interesting stations coming and going and collecting spectacular (-ish) results in a single night this way. Broadcast schedules have to be studied, current “hardcore” DX targets identified… and I have to admit that I’m out of that loop currently. Just turning the knob and recording whatever is populating the bands, and doing that between 21-22:00 UTC, when all programs are directed towards anywhere except Europe turned out to yield pretty boring results. Here it goes anyway:

Video: Browsing the most important BC bands

CONDX and antenna:

The antenna I was using in these videos was a simple wire running up a 10m/33′ fiberglass pole, forming a very archetypical “monopole” or “Marconi” antenna, just a vertical wire, no counterpoise, no matching network, no un-un, transformer or flux capacitor. I planned on using this to make some experiments about the practical benefits (for reception) of all the components it’s now lacking, but it already demonstrates that the beauty of receive-only antennas is that they often don’t require crazy efforts: On the conductive soil at the dike it works pretty well (good signals all over the bands and sufficiently low takeoff angle) as it is.

The evening and the 2 full nights at the dike once again had condx that nobody would phone home about:

SFI, A and 3-hourly K-indices while I was at the dike.

It’s not that these numbers always fully explain actual and current condx but decreasing SFI and rising A/K-indices mean low expectations. Despite the condx still characterized by the solar minimum that way, the location is always delivering proper DX for my radios. Unless stormy or severely unsettled geomagnetic conditions give DX a day off, there’s almost always something to take home, be it a new country, a rare island, unexpectedly loud signals from the other end of the planet at unusual times and/or on unusual bands or other ionospheric mysteries.

Speaking of location: These videos demonstrate the properties of that listening post as much as the capability of the IC-705 to harvest them, and they don’t put that into relation to other radios, so you have to rely on my word on this: Compared to what I brought to that place so far it’s jaw-droppingly good, but a big contributor to that is that only few of my other radios can really cope with the antennas I like to use out there in first place. A radio like the IC-705 is sure making the most out of location and antenna, but it’s not the key component because a low-noise location is everything, it always was and it is today more than ever. Without it, radios and antennas can’t really play their jokers.

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The Icom IC-705: Is this really a new holy grail SWL/BCL receiver?

Many thanks to SWLing Post contributor, 13dka, who shares the following guest post:


The Icom IC-705: Is this really a new holy grail SWL/BCL receiver?

by 13dka

When Thomas got wind of its development in 2019 he immediately asked “could the Icom IC-705 be a shortwave listeners holy grail receiver?”. I usually wince a little when I hear “holy grail” because it means very different things to different people, it’s also a moving target with many people aiming at the spot where it was decades ago. But Thomas certainly had a very level-headed assembly of technical performance, quality and practicality requirements in mind when he used that term, and I thought he might be onto something!

There are some excellent, trustworthy reviews of the IC-705 out there. The following is not one of them, I just want to share an opinionated breakdown on why I think this is an interesting radio for SWLs/BCLs indeed, also deliberately ignoring that it’s actually a transceiver.

Jumping shop

While the era of superhet/DSP-supported tabletop holy grails ended with the discontinuation and sell-off of the last survivors more than a decade ago, powerful PC-based SDR black boxes were taking over the mid-range segment and it became very slim pickings for standalone SWL receivers: Thomas just recently summed up the remaining options here.

Between the steady supply of inexpensive yet serviceable Chinese portables, upgraded with a least-cost version of DSP technology, and the remnants of the high end sector there’s very little left to put on the wish list for Santa – that doesn’t need to be paired with a computer that is.

No surprise that SWLs/BCLs in search of new quality toys with tangible controls are taking a squint over the fence to the ham transceiver market: Hams are still being served the best and the latest in radio technology in all shapes and sizes, and even entry-level rigs usually come with feature-rich general coverage receivers. But transceivers never had SWLs much in their focus in the past decades, and particularly not BCLs: Frontend adaptation, additional AM filters, switches and functions would’ve meant increasing costs and so transceivers were never perfected for that purpose. DSP and SDR technology allowed for improvements on that without actually adding (much) hardware and so some interesting alternatives surfaced in the past years, but most of them still come with little downers, at least for BCLs.

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Social DXing: Looking back at one very radio-active year

One year ago, I posted an article about making the most of social distancing as the world started locking down due to the rapid spread of Covid-19. Here in March 2021, the news is looking much better: vaccines are being distributed at a record pace across the globe and number of cases and deaths are mostly on the decline.

Looking back

As I look back at the Social DX Bucket List I made last year, I’m happy to see that I actually accomplished about 64% of the goals I listed. I knew some of those goals would take well over a year to achieve (the QRP EME one especially).

In particular, I’m chuffed that I braved up and started doing Parks On the Air (POTA) and Summits On The Air (SOTA) activations in CW (Morse Code). That was a huge step for me and I’ll freely admit: I was nervous about it. But in July 2020, I managed to do my first CW activation and since then it has become my choice mode of operating in the field. CW is such a simple mode and so efficient–plus it gives me a sense of connection with the roots of radio communications.

I also accomplished a few things I never set out to do:

Not a typical radio year for me

In a “normal” year, I do way more SWLing than I do ham radio activity.

Last year, I started doing caregiving for my parents in my hometown–I’m typically there 2-3 days a week. While I’ve done shortwave listening and even a little MW DXing in my hometown, I typically don’t have a lot of time, especially in the evening hours. I just want to hit the sack early. QRM is also debilitating there and while I’d like to install a permanent Loop On Ground antenna to mitigate the noise (you heard that right, Andrea!) I’m not entirely sure I’d even have the dedicated listening time to justify it. When I’m there, I like to spend quality time with my folks.

In general, I’ve had much less free time. Indeed, if you’ve written to me via email, you’ll know this based on how long it’s taken me to reply. It can take several weeks especially if the reply requires a detailed response (which many do).

En route to, and on the way back from my hometown, I’ve found that doing park and summit activations has been very rewarding. Last year, I believe I completed a total of 82 park activations.

POTA has given me an excuse to explore public lands I’ve never visited before. Plus, I love nothing more than taking radios to the field–both receivers and transceivers.

Hamming and SWLing

At the end of the day, I’m an SWL and a ham radio operator. I find the two activities complimentary.

Side note: As I mentioned in my Winter SWL Fest presentation this year, it saddens me when I receive angry emails from readers after I post items that are ham radio related. We’ve upwards of 7,000-10,000 daily readers on the SWLing Post and the number of complaints are a teeny, tiny fraction of our readership. I only receive messages like this about once a month and they typically say something akin to “I don’t like the ham radio stuff, so if you don’t stop posting it, I’m leaving!” (FYI: That’s a real quote taken from the last one I received in January). I can only assume that at some point in the past, a ham radio operator has been a jerk to this and other radio enthusiasts. It’s a shame, too. I hate seeing the negative impact of one loud troll compared with the encouragement and support of much better people. All of my ham radio friends are not only supportive of SWLing, but almost all got their start in radio via the shortwaves. I’m certainly a case in point.

I love all things radio and I believe the SWLing Post is a reflection of that. If it offends you, then it might make sense to surf somewhere else.

Now where was I? Oh yeah…

POTA and SOTA outings have helped to satisfy some of my travel cravings as well. I miss going to radio conventions, hamfests, and especially traveling internationally with my family. We are a family who love national parks, forests, and other wildlife areas. Having an excuse to explore public lands we haven’t visited before has been amazing fun.

After POTA activations, I’ll often do a little SWLing since I already have an external antenna up and it’s typically connected to a good general coverage transceiver in a spot with zero RFI or QRM. I’ve especially enjoyed my DXing sessions with the superb Icom IC-705.

Listening habits

One indicator that I did less radio listening last year was the low number of recordings I made. I checked my audio folder recently and saw that I only made a couple dozen recordings–most were staple broadcasters, not rare or special DX.

At the end of the day, I realize that when I do SWLing sessions I like to have dedicated time–at least an hour or two–with headphones on, losing myself on the radio dial.  I simply haven’t had many opportunities this past year to make that a reality.

That’s okay, though. The great thing about the shortwaves is that they’re always there, patiently waiting for us to dive back in!

Looking forward

I’m really not sure what’s in store for me this year, but I know it’ll involve a lot of radio time and that pleases me to no end. I’ve made a few fun goals, but my hope is that, by the end of the year, I may even be able to do some proper travel–maybe even take a flight!

I do know this: I have an even more profound appreciation for my radio enthusiasm as I realize it’s the perfect space to travel and explore the world no matter how “locked down” things are. Based on feedback from readers and contributors to this site, I know I’m not the only one who feels this way.

How about you?

Did your radio activity change or pivot this past year? Did you have more or less time to hit the airwaves? Please comment!

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How to build a PC keyer and AM modulator for the EMTX emergency transmitter

Many thanks to SWLing Post contributor, Kostas (SV3ORA), for sharing the following guest post which originally appeared on his radio website. Note that this project builds on the EMTX emergency transmitter project:


PC keyer and AM modulator: A 15-components versatile keyer and powerful PSU modulator for the EMTX (Emergency Transmitter)

by Kostas (SV3ORA)

Schematic of the keyer and modulator (on the left) for the EMTX. The EMTX schematic is shown as well on the right, to determine the connections to the keyer/modulator.

Introduction

My very successful emergency transmitter (EMTX) was only capable of CW or other slow speed ON/OFF keying modes. Then I thought, why not “give voice” to the design? CW is good, but it is half of the fun. If you could use your simple CW transmitter to send out your voice as well, this would be great. You could now chat comfortably on the nets or use any digital radio amateur mode and have much more fun. The simplest modulation you can apply to an existing CW transmitter, is the AM modulation. And whereas this is an old modulation, mostly abandoned by HAMs due to beeing inefficient, there are still AM nets on HF. But do not forget, AM can also be heard by SSB receivers by zero-beating the receiver to the AM carrier. So you could still use your simple AM transmitter to QSO with the SSB guys!

Along with the modulator, there is also a versatile keyer embedded to the circuit, so that the EMTX can be manually keyed with different ways or automatically keyed by audio tones from the PC. For more information on the keyer, keep reading.

The AM modulator

In the old days, the most common way to apply AM modulation was to modulate the high voltage to the plate of the tubes, using a transformer and a powerful audio amplifier. In low voltage solid state circuits, you can still do it using transformers, but you can also use series transistors instead of the transformer. All these things require many components and/or powerful AF amplifiers if one is to modulate higher power transmitters. This does not match the keep-it-simple design I am trying to achieve here.

So I thought of a simple trick with the use of the extremely common LM317 regulator, used as a modulated power supply. This modulator uses just a few common cheap components and it is able to achieve remarkably good modulation levels for it’s parts-count, just from line audio input. It juices every bit of the internal circuicity of the LM317, just look at where the base current of the 2N2222 comes from.

The AM modulator is a kind of novelty. Whereas there is nothing special in a modulated power supply, this circuit has some interesting properties. It is amazingly sensitive and it is able to provide lots of modulated current to any low power transmitter that it can feed. It can be easily driven by the line output of any laptop (around 20% volume) and provide a very good depth modulation to the transmitter. Charles Wenzel was kind enough to do a simulation on the circuit I developed, which is shown below.

His simulated circuit is a slight variation (for measurement purposes). The resistor to ground on the base stabilizes the bias and the ratio of R1 and R2 set the output voltage (0.6 volts across R2 gives about 8 volts across R1). He put in an emitter resistor just for good measure. Same for the series resistor from the source. Charles words, “I don’t know how believable these results are but it looks pretty darned good!”.

The circuit is being used as a current booster, the current being the supply to the transmitter and dependent on the voltage it produces. The LM317 always tries to keep 1.25V between it’s output pin and “adj” pin but where we benefit here is the current at the “adj” pin is very low, so it is easier to apply audio to it. Effectively, the error amplifier inside the voltage regulator is used as an additional amplifier stage. The output pin voltage varies according to the voltage on the “adj” pin so if we use it to bias the transistor we get negative feedback which improves the quality of the modulation. More output voltage = more bias current = lower output voltage. The result, is a very cheap, low components-count, very sensitive AM modulator that can supply lots of power to easily drive the transmitter and produce a clean and deep AM modulation!

The AM modulator bias is set with the 1M potentiometer. Depended on the bias level, the idle carrier on the EMTX can be set from about 0.5W all the way up to 8W. Needless to say that this modulator can modulate any similar power transmitter, not just the EMTX.

The keyer

If it is to modulate the EMTX from the PC, so as to use the different digital modes, there must be a way to key it also from the PC. This is why I decided to embed into the same circuit, a PC keyer which is triggered by the line audio of the PC, but also triggered manually (internal or external key). Keying by audio tones was decided, because modern PCs do not have LPT ports to trigger directly by DC. This keyer uses a reed relay to reliably, fastly and scilently key the EMTX, which is activated by a transistor. The base current for the transistor is derived from the audio signal after rectification. The incoming audio from the PC line passes through the mini audio transformer to increase its voltage, it is rectified and then charges the shunt capacitor to drive the base of the transistor. The keyer “speed” (decay) is determined by the shunt capacitor size. The circuit starts to trigger from about 50-60% of my sound card output signal level.

The relay used to key the EMTX, must be able to tolerate at least 1A of switching and carrying current. Note that the relay contacts switching current is not the same as the contacts carrying current. Reed relays are the best especially if you want long relay life, noiseless operation and very fast switching speeds, like the ones used in Hellshreiber. If you can’t find such a relay, you can use a reed switch capable of 1A of switching and carrying current and then place a suitable electromagnet close to it, so you can build the relay yourself. If you do so, find the best point where the reed switch responds to the electromagnet.

The keyer relay must be as close as possible to the emitter of the transistor used in the EMTX. The connectors at the back of the EMTX and the keyer/modulator have been physically placed so that when the two units are side by side, a very short link cable is required for this purpose. With the two devices placed close together, you can now use any length of cable for your manual external key, which is now connected to the “EXT” connector of the keyer/modulator.

The keyer does also have an internal mini straight key. I find this idea very nice, to avoid extra cables. It is not the most convenient key in the world, but it is there along with the transmitter every time you need it. By using a special panel switch from apem, I was able to triple this switch usage for the different modes of the keyer. The vinyl lever cap you see in the next picture, is the original part of the switch, to make it easier to key with your finger. But you may build such a part on your own, to fit on other switches types.

The switch is an ON-OFF-(ON momentary) switch type. In the default (middle) position, only the PC keying action is activated. In the top position (ON), the keyer is always active, which is useful for broadcasting audio (into a dummy load). The bottom (ON momentary) position, is the manual PTT action. This is used as a straight key on OOK operation, or as a PTT on AM voice operation. Simple and effective!

Initially, I used one channel of the PC sound card for triggering the keyer and also as an AF signal for the AM modulator, but this caused several problems of unreliable keying or distortion. So I decided to use a second separate AF input (KAF) to key the keyer. This second input, uses the other channel of the stereo sound card. With the addition of this input, there is no interaction between the keyer and the modulator. The AF levels that the keyer and the modulator require, can be set independently. Instead of adding more hardware for the purpose, I have chosen to set these levels by adjusting the volume and the balance of the sound card, which works great. Also, programs like Fldigi, have options for using one of the two channels of the stereo sound card as a keying interface (PTT channel), which makes the keying efen more reliable. When the program is in transmit mode, a continuous tone is heard on the PTT channel. This steady tone, is used by the keyer as a reliable keying signal, independent of the audio signal of the digital mode that modulates the modulator. This solution works very reliably for any mode. But if the program you are using does not have an option for a PTT channel, that is ok, as the keyer works reliably even without this feature. For voice communication or broadcasting music (into a dummy load) you just use the internal key switch as a PTT to handle these modes.

Results

Prior to building the keyer and the modulator in the same device, I had tested the circuits independently quite a few times, to ensure the results can be reproduced. The modulation quality and depth out of the AM modulator have to be listenned to be believed. I have not made any linearity measurements, I just trust my ears on this one. It works great on music as well as on voice. Apart from that, this is the most sensitive AM modulator I have ever built, requiring only a small fraction of the line level output of the PC sound card.

When modulated by this modulator, the EMTX shows no audible signs of FM modulation. I switched my receiver to SSB and I could perfectly zero beat the AM modulated music signal which stayed on frequency and it’s tone did not change during loud audio signal music. Switching back and forth from SSB to AM modulation on the receiver, I did not notice any difference in the audio quality, apart of course from the narrower bandwidth on SSB modulation, due to the narrower IF filter inside the receiver on SSB.

The AM/OOK switch is used to select the modulation applied to the EMTX. When the keyer is set to be triggered by audio from the PC, at the OOK position, the EMTX is just switched on and off by the audio tones applied to the keyer, or by the manual key, internal or external (connected to the “EXT” connector). At AM position, the EMTX is switched on by the audio signal applied to the KAF connector and at the same time AM modulated by whatever audio signal is applied to the AF connector. On voice communications, the momentary position of the internal key is used as a PTT. On music broadcasting (into a dummy load) the non-momentary position of the internal key is used to keep the keyer always active.

Photos

Back connections to the EMTX.

Pictures of the finished keyer/modulator. You don’t have to build it that nice-looking if you don’t care.

Modulator prototype and EMTX built on a breadboard. Yes it worked just fine onto a piece of wood.


Thank you so much for sharing this brilliant and simple project with us, Kostas. Your handiwork is absolutely brilliant too!

Click here to check out Kostas’ website.

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Icom IC-705 firmware v1.20, programming software v1.10, and a new 3rd party remote app for Android

Many thanks to SWLing Post contributor, Markku Koskinen, who notes the following new and updated programs for the Icom IC-705 general coverage transceiver:

First, Icom has published firmware version 1.20 which includes a number of new features. We’ll post the full announcement below. Click here to view the release notes and download.

Secondly, Icom has published a new version (1.10) of their IC-705 programming software. The new release also includes a number of additions. Click here to view the release notes and download.

Finally, Markku notes that there is now an IC-705 Remote application on the Google Play app store.

The app appears to control basic functionality like tuning, band, mode, filter, and CI-V address switching.  The app is free and should work on most Android devices.

Thanks for the tips, Markku!

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